61631280 has 100 divisors (see below), whose sum is σ = 214077072. Its totient is φ = 16433280.

The previous prime is 61631267. The next prime is 61631287. The reversal of 61631280 is 8213616.

61631280 is a `hidden beast` number, since 6 + 1 + 631 + 28 + 0 = 666.

61631280 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (61631287) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1725 + ... + 11235.

Almost surely, 2^61631280 is an apocalyptic number.

61631280 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61631280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107038536).

61631280 is an abundant number, since it is smaller than the sum of its proper divisors (152445792).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

61631280 is a wasteful number, since it uses less digits than its factorization.

61631280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9536 (or 9521 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 61631280 is about 7850.5592157502. The cubic root of 61631280 is about 395.0030016329.

Adding to 61631280 its reverse (8213616), we get a palindrome (69844896).

The spelling of 61631280 in words is "sixty-one million, six hundred thirty-one thousand, two hundred eighty".